1. Field of the Invention
The present invention relates to a multilayer ceramic capacitor, and more particularly, to a multilayer ceramic capacitor capable of controlling equivalent series resistance (ESR) characteristics.
2. Description of the Related Art
In accordance with the recent trend toward miniaturization in electronic devices, the use of a surface mounting substrate has increased. Therefore, chip components mounted on the surface mounting substrate have been continuously miniaturized. A capacitor, which is one of these chip components, has been widely used for various purposes in analog and digital electronic circuits.
A capacitor, an element capable of storing electricity therein, basically includes two electrodes opposing each other, such that when voltages are respectively applied thereto, electricity is accumulated in each of the electrodes. In a case in which a direct current (DC) voltage is applied to the capacitor, a current flows in the capacitor during the accumulation of electricity, yet does not flow therein when the accumulation of the electricity is completed. In addition, in the case in which an alternate current (AC) voltage is applied to the capacitor, polarities of the electrodes are alternated, such that an AC current continuously flows therein. The performance of the capacitor is represented by capacitance F. A multilayer capacitor capable of implementing high capacitance in spite of having a small size has been widely used. Particularly, the multilayer capacitor is widely used as a decoupling capacitor connected between a semiconductor chip and a power supply in a power supply circuit of a large scale integrated circuit (LSI), or the like.
Meanwhile, in order to be used in a central processing unit (CPU), a multilayer chip capacitor needs to have excellent decoupling characteristics. That is, it order to be used as a decoupling capacitor of the CPU, the multilayer chip capacitor needs to have: 1) low equivalent series inductance (ESL), 2) high capacitance, 3) an appropriate level of equivalent series resistance (ESR), 4) high temperature reliability, and the like. However, when the number of stacked layers is increased in order to implement high capacitance, an ESR value is reduced and a parallel resonance phenomenon between capacitors has been caused due to parallel connections between capacitors. However, when the ESR value of the capacitor is increased, an impedance curve becomes flat according to a frequency, and when capacitors having different capacitances are connected in parallel with each other, the parallel resonance phenomenon is also suppressed. Therefore, there is a need to more practically control the ESR characteristics of the capacitor.